Cooling fan



FIG. 1 is a front and top perspective view of a cooling fan, showing my new design;

FIG. 2 is a rear and bottom perspective view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a left side elevation view thereof;

FIG. 6 is a right side elevation view thereof;

FIG. 7 is a top plan view thereof;

FIG. 8 is a bottom plan view thereof; and,

FIG. 9 is another perspective view thereof, shown in an alternative position.

The broken lines in the figures illustrate portions of the cooling fan that form no part of the claimed design. 

CLAIM The ornamental design for a cooling fan, as shown and described. 